Replacing contaminated and toxic Cd deposit layer with high corrosion resistance Zn-Ni/nanosilica alloy deposit layer to meet the requirements of environmental friendly and high technological products.Replacing contaminated and toxic Cd deposit layer with high corrosion resistance Zn-Ni/nanosilica alloy deposit layer to meet the requirements of environmental friendly and high technological products.

- Theoretical results: deployed subjects

Subject 1: Research and manufacture Zn-Ni/nanosilica alloy deposit layer on carbon steel substrate.

a) Task 1: Research dispersion of nanosilica in Zn-Ni plating solution and determine the nanosilica particle size in plating solution.
b) Task 2: Research effect of parameters: pH, current density, stirring speed, temperature.

Subject 2: Research effect of Ni content in alloy on the corrosion resistance of Zn-Ni and Zn-Ni/nanosilica alloy deposit layers.

a) Task 1: Research corrosion rate of Zn-Ni and Zn-Ni/nanosilica alloy deposit layers (with different Ni content) immersed in 3% NaCl solution by weight loss determination method.
b) Task 2: Research and compare corrosion resistance of Zn-Ni and Zn-Ni/nanosilica alloy deposit layers (with different Ni content) by potentiodynamic polarization method.
c) Task 3: Investigate electrochemical impedance spectroscopy of Zn-Ni and Zn-Ni/nanosilica alloy deposit layers (with different Ni content).

Subject 3: Research effect of nanosilica content on corrosion resistance of Zn-Ni/nanosilica deposit layer.

a) Task 1: Research corrosion rate of Zn-Ni and Zn-Ni/nanosilica alloy deposit layers (with different nanosilica content) immersed in 3% NaCl solution by weight loss determination method.
b) Task 2: Research and compare corrosion resistance of Zn-Ni and Zn-Ni/nanosilica alloy deposit layers (with different nanosilica content) by potentiodynamic polarization method.
c) Task 3: Investigate electrochemical impedance spectroscopy of Zn-Ni and Zn-Ni/nanosilica alloy deposit layers (with different nanosilica content).

Subject 4: Research and compare structure, morphology of Zn-Ni and Zn-Ni/nanosilica alloy deposit layers.

Subject 5: Test, investigate and compare corrosion resistance under accelerated test conditions of Zn-Ni and Zn-Ni/nanosilica alloy deposit layers.

a) Task 1: Manufacture 150 dm2 of Zn-Ni/nanosilica deposit layer (150 samples of size 100×50×1 mm) and 150 dm2 of Zn-Ni deposit layer (150 samples of size 100×50×1 mm.
b) Task 2: Carry out neutral salt spray acceleration test; evaluate and compare corrosion resistance of Zn-Ni and Zn-Ni/nanosilica alloy deposit layers.

Subject 6: Develop technological process for plating of Zn-Ni/nanosilica alloy; manufacture 200 dm2 of Zn-Ni/nanosilica deposit layer.

Subject 7: Final report of the project.

- Applied results:
Develop technological process for plating of Zn-Ni/nanosilica alloy; manufacture 200 dm2 of Zn-Ni/nanosilica deposit layer. Area of Zn-Ni/nanosilica deposit layer: 200 dm2.
01 utility solution "The process of plating zinc-nickel-nano silicon oxide alloy coating on carbon steel substrate" is accepted as a valid application under Decision No. 7348/QD-SHTT dated January 21, 2020 of the Intellectual Property Office.

- Successfully put nanosilica into Zn-Ni/SiO2 alloy deposit layer.
- Successfully manufacture Zn-Ni/nanosilica alloy deposit layer (at current density of 3 A/dm2 and plating time of 20 minutes).
- Successfully replace contaminated and toxic Cd deposit layer with high corrosion resistance Zn-Ni/nanosilica alloy deposit layer to meet the requirements of environmental friendly and high technological products.

- Scientific papers in referred journals (list):
+ International journals:

• 01 SCI: Nguyen Thi Thanh Huong, Le Duc Bao, Le Ba Thang, Nguyen Van Chien, Truong Thi Nam, Nguyen Van Khuong, Corrosion behavior of electrodeposited ZnNi alloy – CeO2 modified SiO2 particle composite coatings. Russian Journal of Physical Chemistry A, 2021, Vol. 95, No. 4, pp. 827–833. ISSN 0036-0244. DOI: 10.1134/S0036024421040099.
• 01 ISSN: Nguyen Thi Thanh Huong, Le Ba Thang, Le Duc Bao, Truong Thi Nam and Nguyen Van Chien, Corrosion Resistance of ZnNi/Nanosilica Alloy Coating on Carbon Steel, Elixir Corrosion & Dye 134 (2019) 53588-53592.

+ National journals:

• Nguyen Thi Thanh Huong, Le Ba Thang, Dao Bich Thuy, Le Duc Bao, Effects of current density and plating time on corrosion resistance of ZnNiSiO2 deposit, Journal of Science and Technology (submitted for publication 14/2/2020)

- Patents (list):
01 utility solution "The process of plating zinc-nickel-nano silicon oxide alloy coating on carbon steel substrate" is accepted as a valid application under Decision No. 7348/QD-SHTT dated January 21, 2020 of the Intellectual Property Office.

- Technological products (describe in details: technical characteristics, place):
Area of Zn-Ni/nanosilica deposit layer: 200 dm2.

- Other products (if applicable):

• 01 chapter of book: Nguyen Thi Thanh Huong, Le Ba Thang, Nguyễn Tuấn Anh, Chapter 25 - Inhibitor-loaded silica nanoparticles for self-healing metal coating in “Smart Nanocontainers”, Elsevier Publishing, 2020, Pages 431-441, ISBN: 9780128168912.

Request the Vietnam Academy of Science and Technology to provide funding for us to continue implementing the pilot production project to complete the project's products before commercializing the product.